Move $peers service account-related methods to Account - Closes #169

[slaweet]

Expected behaviour

peers service should contain only code related to setting and maintaining a connection to a peer.

Actual behaviour

peers service contains definitions of the following methods that result in a server call:

• listTransactions
• getStatusPromise
• sendLSKPromise
• listTransactionsPromise
• setSignature

All of them are related to an account, so they should be moved to another service: account

Closes #169

[coveralls]

Coverage increased (+0.4%) to 86.364% when pulling c538a18 on 169_refactor-peers into 99b6c1c on development.

[coveralls]

Coverage increased (+2.3%) to 88.235% when pulling 326b381 on 169_refactor-peers into 99b6c1c on development.

[coveralls]

Coverage increased (+2.3%) to 88.235% when pulling 326b381 on 169_refactor-peers into 99b6c1c on development.

[coveralls]

Coverage increased (+2.3%) to 88.235% when pulling ffd5133 on 169_refactor-peers into 99b6c1c on development.

[coveralls]

Coverage increased (+2.8%) to 88.7% when pulling e017f5a on 169_refactor-peers into 99b6c1c on development.

[coveralls]

Coverage increased (+2.3%) to 88.235% when pulling ffd5133 on 169_refactor-peers into 99b6c1c on development.

[coveralls]

Coverage increased (+2.1%) to 88.018% when pulling 8d18079 on 169_refactor-peers into aeed7b2 on development.

[coveralls]

Coverage increased (+2.1%) to 87.461% when pulling 178aa20 on 169_refactor-peers into 597c535 on development.