Remove master/slave terminology

Fixes cockroachdb#7534.

v1.0/simplified-deployment.md

@@ -4,7 +4,7 @@ summary: Deploying CockroachDB is simple and straightforward.
 toc: false
 ---
 
-Deploying and maintaining databases has forever been a difficult and expensive prospect. Simplicity is one of our foremost design goals. CockroachDB is self contained and eschews external dependencies. There are no explicit roles like masters, slaves, primaries, or secondaries to get in the way. Instead, every CockroachDB node is symmetric and equally important, meaning no single points of failure in the architecture.
+Deploying and maintaining databases has forever been a difficult and expensive prospect. Simplicity is one of our foremost design goals. CockroachDB is self contained and eschews external dependencies. There are no explicit roles like primaries or secondaries to get in the way. Instead, every CockroachDB node is symmetric and equally important, meaning no single points of failure in the architecture.
 
 -   No external dependencies
 -   Self-organizes using gossip network

v1.1/simplified-deployment.md

@@ -4,7 +4,7 @@ summary: Deploying CockroachDB is simple and straightforward.
 toc: false
 ---
 
-Deploying and maintaining databases has forever been a difficult and expensive prospect. Simplicity is one of our foremost design goals. CockroachDB is self contained and eschews external dependencies. There are no explicit roles like masters, slaves, primaries, or secondaries to get in the way. Instead, every CockroachDB node is symmetric and equally important, meaning no single points of failure in the architecture.
+Deploying and maintaining databases has forever been a difficult and expensive prospect. Simplicity is one of our foremost design goals. CockroachDB is self contained and eschews external dependencies. There are no explicit roles like primaries or secondaries to get in the way. Instead, every CockroachDB node is symmetric and equally important, meaning no single points of failure in the architecture.
 
 -   No external dependencies
 -   Self-organizes using gossip network

v2.0/simplified-deployment.md

@@ -4,7 +4,7 @@ summary: Deploying CockroachDB is simple and straightforward.
 toc: false
 ---
 
-Deploying and maintaining databases has forever been a difficult and expensive prospect. Simplicity is one of our foremost design goals. CockroachDB is self contained and eschews external dependencies. There are no explicit roles like masters, slaves, primaries, or secondaries to get in the way. Instead, every CockroachDB node is symmetric and equally important, meaning no single points of failure in the architecture.
+Deploying and maintaining databases has forever been a difficult and expensive prospect. Simplicity is one of our foremost design goals. CockroachDB is self contained and eschews external dependencies. There are no explicit roles like primaries or secondaries to get in the way. Instead, every CockroachDB node is symmetric and equally important, meaning no single points of failure in the architecture.
 
 -   No external dependencies
 -   Self-organizes using gossip network

v2.1/simplified-deployment.md

@@ -4,7 +4,7 @@ summary: Deploying CockroachDB is simple and straightforward.
 toc: false
 ---
 
-Deploying and maintaining databases has forever been a difficult and expensive prospect. Simplicity is one of our foremost design goals. CockroachDB is self contained and eschews external dependencies. There are no explicit roles like masters, slaves, primaries, or secondaries to get in the way. Instead, every CockroachDB node is symmetric and equally important, meaning no single points of failure in the architecture.
+Deploying and maintaining databases has forever been a difficult and expensive prospect. Simplicity is one of our foremost design goals. CockroachDB is self contained and eschews external dependencies. There are no explicit roles like primaries or secondaries to get in the way. Instead, every CockroachDB node is symmetric and equally important, meaning no single points of failure in the architecture.
 
 -   No external dependencies
 -   Self-organizes using gossip network